If this is a carry a lot, shoot rarely, backup on your bow hunts, I would suggest a Remington model 7 in 308. It is light, compact and is pretty much as good as a 30-06 (It pains me to say that because I love the 30-06 for plains game). If you want to limit your cost go for a savage, I don't have personal experience with them but many people claim that they are the most accurate out of the box rifle you can get, and they are cheap. If you want a little less thump, go for a 7mm 08. While they are a little small for the larger plains game, just about everything has been taken with one.